[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) › Patellar cartilage [Skeletal system](https://durgical.com/en/anatomy/system/skeletal-system/) · [Lower limb](https://durgical.com/en/anatomy/region/lower-limb/) # Patellar cartilage The patellar cartilage is the thick, smooth layer on the back of the kneecap; it glides on the femur and is heavily loaded on stairs. Official name: Articular cartilage of patella [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=lower_limb&select=cartilage_patella&side=r) Opens in the Durgical app, no sign-up needed. ## What it is Thick articular cartilage on the back of the kneecap, gliding on the femur's groove. ## What it does Lets the joint glide with very little friction and spreads load across the bone. ## Key points - Patellofemoral load rises with knee flexion and quadriceps force, so squatting, kneeling and stairs load it most - After a lateral dislocation the medial facet strikes the lateral femoral condyle, causing osteochondral fractures and loose bodies - The odd facet, along the far medial edge, touches the femur only in deep flexion ## Key facts **Where** Posterior articular surface of patella **Function** Hyaline articular cartilage; low-friction gliding; spreads load; thickest articular cartilage in the body; avascular, nourished by synovial fluid ## Relations **Behind** Trochlear cartilage of the [femur](https://durgical.com/en/anatomy/femur/); in deep flexion the odd facet meets the medial femoral condyle **Above** Suprapatellar pouch **Below** Non-articular apex and the [infrapatellar fat pad](https://durgical.com/en/anatomy/infrapatellar-fat-pad/) **Deep** Subchondral bone of the [patella](https://durgical.com/en/anatomy/patella/) ## How to find it With the knee straight and relaxed, the patella is pushed to one side and the undersurface of its edge is pressed; tenderness there points to the facet cartilage. ## Examination - Patellar grind (Clarke) test: pain when the quadriceps contracts against a patella held down; common in normal knees too, so of low specificity ## On imaging Axial (skyline) view for patellofemoral joint-space narrowing and lateral tilt; MRI for fissures, defects and the bone-bruise pattern after a dislocation. ## Common problems - Softening and wear behind the kneecap (chondromalacia), often with pain on stairs or squatting. - Osteoarthritis. ## How it is diagnosed Symptoms and exam; X-rays show joint-space narrowing in arthritis; MRI shows cartilage defects. ## Treatment - Physical therapy, weight management, activity changes; medicines or injections for pain. - Surgery for focal defects: microfracture, cell-based repair, or osteochondral grafts (including osteochondral allograft from a donor). - Knee replacement for advanced arthritis. ## Clinical notes - Excessive lateral pressure syndrome: a tight [lateral retinaculum](https://durgical.com/en/anatomy/lateral-patellar-retinaculum/) tilts the patella and overloads the lateral facet - Osteochondral fragments after dislocation may be fixed back if large, or removed if small - Chondromalacia patellae describes softening seen at surgery and does not always match the pain ## Anatomical variants - Bipartite patella: an accessory ossicle, usually at the upper outer corner, joined to the main bone by fibrocartilage; it is often bilateral and has smooth, rounded edges, unlike a fracture ## Development The patella forms as a sesamoid bone within the [quadriceps tendon](https://durgical.com/en/anatomy/tendon-of-quadriceps-femoris-muscle/); it is cartilaginous at birth and ossifies in early childhood from several foci that merge, and an unfused focus explains the bipartite patella. ## Related conditions - [Knee Osteoarthritis](https://durgical.com/en/conditions/knee-osteoarthritis/) - [Patellofemoral Pain Syndrome](https://durgical.com/en/conditions/patellofemoral-pain-syndrome/) - [Patellar fracture](https://durgical.com/en/conditions/patellar-fracture/) ## Test yourself Think of the answer, then tap the question to see it. ## Which activities load the patellar cartilage most, and why? Squatting, kneeling and stairs: patellofemoral load rises with knee flexion and quadriceps force. ## Which osteochondral injury follows a lateral patellar dislocation? The medial patellar facet strikes the lateral femoral condyle, causing osteochondral fractures and loose bodies. ## What is the odd facet of the patella? The far medial edge of the patellar cartilage, which touches the medial femoral condyle only in deep flexion. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/anatomy/articular-cartilage-of-patella/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** cartilago articularis TA2 382 **Official Spanish (DeCS)** Cartílago articular de la rótula DeCS D002358 **English (TA2)** Articular cartilage of patella ## Related - [Patella](https://durgical.com/en/anatomy/patella/) - [Femoral cartilage](https://durgical.com/en/anatomy/articular-cartilage-of-femur/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=2401&filter=ths_termall&q=Cart%C3%ADlago%20Articular); [Anatomy, Bony Pelvis and Lower Limb, Knee](https://www.ncbi.nlm.nih.gov/books/NBK500017/); [9.6 Anatomy of Selected Synovial Joints](https://openstax.org/books/anatomy-and-physiology-2e/pages/9-6-anatomy-of-selected-synovial-joints) (OpenStax (Rice University), 2022) · adapted, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/articular-cartilage-of-patella/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/articular-cartilage-of-patella/